Pneumatic spring for vehicles.



L. R. GRUSS.

PNEUMATIC SPRING FOR VEHICLES. APPLIUATION FILED AUG. 24, 1910.

1,013,487,, Patented Jan, 2, 1912.

UNITED STATES PATE OFFICE,

LUCIEN R. GRUSS, OF CHICO, CALIFORNIA, ASSIGNOR TO THE PNEUMATIC CUSHIONCOMPANY, INC., OF PHOENIX, ARIZONA TERRITORY, A COIR-P0l'\A'J.IOl l'v OFARIZONA TERRITORY.

PNEUMATIC SPRING FOR VEHICLES.

Specification of Letters Patent.

Patented Jan. 2, 1912.

Application filed August 24, 1910. Serial No. 578,741.

To all whomvit may concern:

Be it known that I, LUCIEN R. Gauss, citizen of the United States,residing at Chico, in the county of Butte and State of California, haveinventednew and useful Improvements in Pneumatic Springs for Vehicles,of which the following is a specification.

This invention pertains to pneumatic cushioning means for vehicles.

The object of my invention is to provide a pneumatic cushion for thebodies of automobiles and other vehicles; to provide means whereby thevehicle body is supported on a pneumatic cushion; means whereby thepressure of the pneumatic cushion is created, and means forautomatically replenishing the charge of fluid.

The invention consists of the parts and the construction and combinationof parts as hereinafter more fully described and claimed, havingreference to the accompanying drawings, in which Figure 1 is a sideelevation of aportion of a vehicle showing the device. Fig. 2 is may beof any suitable or desired form, and

may be connected in appropriate manner to the axles, as theexigencies'require. In the present instance, the cylinder is formed of asubstantially U-shapedcasting, and within which, in the chamber 6, is aquantity of fluid 7, which may be oil or other substance,

and upon which the lower head 8 of the piston is adapted to rest. In theother member 9 of the cylinder casing is mounted a cupshaped leather, orothersuitable piston 10,

which is normally pressed down upon supporting lugs 11, by a powerfulspring 12.

' In practice, a suflicientvolume of oil will.

be placed in the lower'chamber 6, and when the load of the body of thevehicle is trans: mitted to the piston.3, and thence upon the surface ofthe oil 7, the latter will rise in the arm 9, and compress apre-determined volume of air below the plston 10.- Under ex 'tremeconditions, as when the vehicle is suddenly excessively jolted andconsequently imposes greater pressure on the flexible oil piston 7,which would then compress the air below the piston 10 to a greaterdegree than the same is designed normally to carry, this sudden greatercompression of air would, if provision were not made to relieve theexcessive pressure, result in not sufliciently cushioning the motions ofthe body of the vehicle. In other words, the resiliency would not beflexible enough and the vibrat-ions of the body of the car would not beeasily and gradually checked. In order then to prevent this disadvantageof the excessive pressure of air in the cushion when extreme loads areimposed, the piston 10 is provided, and after the pressure of air in thechamber 9 reaches a point equal to the downward pressure of the spring12, and then exceeds that downward pressure the piston 10 will graduallylift, compressing air at the same time in the chamber in which thespring 12 is mounted. The advantage of this auxiliary cushion, formed bythe spring 12 and the air contained in the chamber in which it ismounted, is that the oil, under the impulse of piston head 8, againsttheair in the chamber 9, is not suddenly impeded, and when the pressurein chamber 9 has reached such a point as would ordinarily be furthernon-compressible or too stifl to form a reasonably resilient check-tothe vibrations of the car body, then the piston 10 will yield toassistin the checking of the descent of the piston head -8. Manifestly,then, the moment that the vibrations are checked by the cushioningchambers, and the recoil commences the spring 12 will again depress thepiston 10 and the expansible air in the cylinder 9 will force back thefluid piston 7 and lift the piston head 8.'

The piston 10 thus constitutes, in fact, a yielding head for that end ofthe cylinder, between which head and the body of oil 7 is formed an airchamber which is charged with air under pressure in the followingmanner: In order to primarily charge the several air cylinders 9, thereis provlded 0n the body of the vehicle A a suitable compressor 12 drivenby suitable connections with the engine and from the compressor 12 airis delivered a tank 13- from which connections 14 arem'ade to theseveral cylinders- 9. In order to' prevent an excess of pressureaccumulating in the reservoir 13,

an automatic safety valve 15 is mounted therein, and this will open whena predetermined pressure has accumulated in the reservoir. From thelower portion of the tank 13 are extended a plurality of pipes 16adapted to contain oil and which connect with the lowermost portions ofthe U-shaped casting of the cushion. By this means the constant supplyof air is maintained in each of the chambers 9 at uniform pressure, andthe oilforming movable pistons 7 reacting against the superposed aircushion is prevented from moving toward the reservoir by means ofsuitable check valves 16 mounted in the pipes 16 at the point where theyconnect to the several cylinders. In a similar manner, the air as it iscompressed in each of the air chambers 9 is prevented from returningthrough the connections 14 to. the reservoir by meansof check valves 14located in the connections 14 and adjacent the cylinders 9. I

In order 'to constantly keep the pressure under uniform degree in thesystem, I mount a small plunger 18 in the head-19 of eachcylinder 2, andwhich plunger is provided with a small valve 20 which will close whenthe plunger is pushed up by contact with the upper end 21 of the piston3, a quantity of air being compressed and discharged, through a pipe 22,into the air system. Thus, after the system is once charged bythe'compressor 12, the pressure will be kept up by the reciprocation ofthe plunger 18. This is an important feature in that there wouldinevitably occur a .small leakage of the air, and at each reciprocationof the main piston 3 and its abutment against the compression piston 18,a volume of air of such quantity asmay be required would be compressedat each movement of the piston 18. Should the number of reciprocationsof the piston 18 result in an accumulation of more than the desiredpressure in the system, then the automatic safety valve 15 would openand allow the excess to escape. The conductors, 22, which carry thefluid compressed by the pistons, 18, are so connected to the pipe, 14,that the several checkvalves, 14:,v are interposed between theconductors, 22, and'the, cylinders, 9; thus when an excessive pressurehas been accumulated by the automatic compressors, 18, the safety valve,15, will open and prevent any increase of pressure in the severalcylinders, 9.

A spring 23 mounted within the compression chamber 19 will normallydepress the plunger 18 as the piston 3 descends. A fresh volume of airwill pass upwardly through the valve 20 and prevent the formation of avacuum at that point. The piston 18 is reduced in diameter at one partto receive the spring 28 which re-acts against shoulders in the cylinder19 and upon the piston to hold the latter down upon the pistonflange'21, so that when the piston 3 moves up it lifts piston 18 whichwill be forced down by spring 23 when the piston 3 descends.

For the-purpose of preventing a too sudden recoil of the piston 3 in itscylinder 2, the piston is formed with an enlarged head 2 and this will,when ascending, compress a volume of air between its upper surface, andthe top of the cylinder 2 gradually checking the recoil of the piston 3.A small port 25 is provided in the top of the cylinder to admit air topass inwardly and outwardly in small quantities to prevent the formationof vacuum in the operation of the piston, and also to supply air to theupper part of the cylinder 19.

Since one side of the cylinder 2 has a suiiiciently large aperture toreceive the link connection 5 from the body of the car, it is desirableto exclude, as far as possible, the entrance of dust to the interior ofthe casing, and for this purpose I have introduced a diaphragm 26 tocatch such particles of dust as may enter, this diaphragm beingperforated at 27 to allow a small quantity of air to pass back andforth.

Since it is practically impossible to attain perfection in workmanshipand absolutely prevent the escape of oil from the chamber 6 to the uppersurface of the piston head 8, I have found it expedient to form a slightconcave groove 28 around theupper surface of the piston head for thecatching of such oil as will get past the piston 8, and in order toavoid, as far as possible, personal inspection at frequent intervals ofthe several resilient cushions by the machine-driver, it is deasirableto automatically return the escaped oil back to the cylinder6. Toaccomplish this, I have mounted a small plunger 29 in the piston 8,which, when raised sufficiently to abut the diaphragm 26, will theneject a volume of oil from the duct 30, past a check valve 31 and intothe chamber 6.

The oil in the chamber 30 is prevented from passing upwardly and intothe groove 28 by means of a small check "alve 32 suitably mounted in acanal 33 which conveys the oil from the groove 28 downwardly to thechamber 30. It will then be seen that at each reciprocation of thepiston 8 the plunger 29 will be carried against the diaphragm 26 andwill be relatively depressed into the piston 8, thus ejecting, as beforestated, a quantity of the fluid back into the chamber 7. This feature ofthe invention obviously avoids any personal attention being devoted tothe spring system, as also does the feature of automatically sustainingthe desired pressure in the air chambers, by means of theauxiliarycompressors 18.

In operation, it is first necessary, after the cylinders have beencharged with a suflicientl volume of oil, to compress by means of thecompressor 12, a sufiicient Volume of air in the container 13 to thedesired pressure, this pressure, of course, being determined by theweight of the load of the vehicle to be supported, and then after thereservoir 13 has been charged it is no longer necessary to run thecompressor, as all of the system will be equally charged with fluidpressure. When the vehicle is running the possible leakage of air isremedied by the automatic operation and charging of the auxiliarycompressors 18, of which there is one for each of the cushions, and ateach reciprocation of the plunger 18 a small volume of air will be addedto the system, thus keeping the pressure up to the normal degree, excessbeing relievedas necessary by the valve 15. The machine is alsoautomatic in the replacement of the leak oil at the several cylinders 8,when the car is in operationyand when tlle car is not running oil whichmay possibly escape may be caught .in a suitable trap 34, one of whichis suitably mounted in such position to catch the excess leak oil fromwithin the cylinders. I

Having thus described my invention, what I claim and desire to secure byLetters Patent is 1. The combination in a vehicle, of the body and anaxle thereof, an air cylinder .supported on one of said parts and apiston connected to' the other of said parts and working in thecylinder, an air compressor on the vehicle connected with the cylmder tomaintain an air pressure therein and provide an air cushion forthepiston, and means whereby the air pressure within the air cushion isautomatically recharged during the running of the vehicle, said-meansincluding auxiliary air compressors within the cylinder operable by thepiston independently of the engine.

2. The combination in a vehicle, of the body and an axle thereof, an aircylinder supported on one of said parts and a piston connected to theother "of said parts and working in the cylinder, an air compressor onthe vehicle connected with the cylinder to maintain an air pressuretherein and provide an air cushion for the piston, and means whereby theair pressure within the air cushion is automatically recharged duringtherunning of the vehicle, said means including air compressing plungersmounted in the cylinder and actuated by the reciprocation of the piston.

3. The combination in a vehicle, of the body and an axle thereof, an aircylinder supported on one of said'parts and a piston con-' nected to theother of said parts and working in the cylinder, an air compressor onthe vehicle connected with the cylinder to maintain an air pressuretherein and provide an air cushion for the piston, and an airreservoirand connections between said reservoir and the cylinder wherebyan even pressure is maintained, and means for automatically rechargingthe air pressure as the latter is reduced by leakage, saidv meansincluding compressing plungers in the cylinder and actuated by thepiston.

4. The combination in a vehicle, of the body and an axle thereof, an aircylinder supported on one of said parts and a piston connected to theother of said parts and working in the cylinder, an air compressor onthe vehicle connected with the cylinder to maintain an air pressuretherein and provide an air cushion tor the piston, an air reservoir andconnections between said reservoir and the cylinder whereby an evenpressure p is maintained, means for automatically recharging the airpressure as the latter is reduced by leakage, said means includingcompressing plungers in the cylinder and actuated by the piston, and asafety valve connected to said pressure reservoir and adapted toautomatically relieve any excess of pressure.

5. The combination in a vehicle, of the body andan axle thereof, an aircylinder supported in one of said parts and a piston connected to theother 'of said parts and working in the cylinder, an air compressor onthe vehicle connected with the cylinder to maintain an air pressuretherein and provide an air cushion for the piston, an air reservoir andconnections between said reservoir and the cylinder whereby an evenpressure is maintained, means for automatically recharging the airpressure as the latter is reduced by leakage, said meansincludingcompressing plungers in the cylinder and actuated by thepiston, a safety valve connected to said pressure reservoir and adaptedto automatically relieve any excess of pressure, and an auxiliarypneumatic cushion adapted to come into operation after a pre-determinedpressure has been reached in the pneumatic cushion.

6. The combination in a vehicle 'of the body and an axle thereof, an.air cylinder supported on one of said'parts and a piston connected tothe other of said parts and working in the cylinder, an air compressoron the vehicle connected with the. cylinder to maintain an air pressuretherein and provide an air cushion for the piston, an air reservoir andconnections between said reservoir and the cylinder whereby an evenpressure is maintained, means for automatically recharging theairpressure as the latter is reduced by leakage, said means includingcompressing plunger-s in the cylinder and actuated by the piston, asafety valve connected to said pressure reservoir and adapted toautomatically relieve any excess of pressure, and an auxiliary pneumaticcushion adapted to come into operation after a predetermined pressurehas been reached in the pneumatic cushion, said auxiliary cushionincluding an air compressing plunger and adapted to yield when saidpre-determined pressure has been attained.

7. The combination in a vehicle of the body and an axle thereof, an aircylinder supported on one of said parts and a piston connected to theother of said parts and working in the cylinder, an air compressor onthe vehicle connected with the cylinder to maintain an air presshretherein and providean air cushion for the piston, an-air reservoir andconnections between said reservoir and the cylinder whereby an evenpressure is maintained, means for automatically rechargingbthe airpressure-as the latter is reduced y leakage, said means includingcompressing plungers in the cylin der and actuated by thepiston, asafety valve connected to said pressure reservoir and adapted toautomatically relieve anyexcess of pressure, an auxiliary pneumaticcushion adapted to come into operation after a predetermined pressurehas been reached in the pneumatic cushion, said means including an aircompressing plunger and adapted to yield when said pre-determinedpressure has been attained, and-aresilient member reactive against saidpiston.

8 The combination in a vehicle of a body and an axle thereof, asubstantially U- shaped air cylinder supported on one of said parts, apiston in said cylinder connected to the other of said parts, saidcylinder con-r. taining a fluid in the lowerportion between the twoparts -.of the cylinder and upon which fluid the piston is effective achamber in the cylinder containing air above the 7 fluid, means forcreating an initial pressure in the air chamber, means whereby saidpres-' the operation of the vehicle, and an au 'ary resilient cushionand means whereby the volume of fluid in the cylinder is maintained,

9. The combination with a vehicle, of a fluid compresser, an axle, acylinder connected to the axle, a piston operable in said-cylinder andconnected to the vehicle body, said 7 cylinder having a reservoircontaining fluid and liquid, conducting connections between thereservoir and the cylinder, an automatic releasing valve adapted-to openafter a predetermined pressure has accumulated vwithin the reservoir,and means mounted in the cylinder and adapted to be actuated by thereciprocation of the piston to automatically sustain the predeterminedpressure within the reservolr.

10; The combination with a vehicle and its axle 'ofan air reservoir, acylinder, a p15- ton operable within said cylinder a fluid'below saidpiston in the cylinder, connections between the cylinder and thereservoir whereby the reciprocation of the piston will I compress theair within the reservoir, means erable in conjunction with the pistonere'by a predetermined pressure 0 air in the reservoir may beautomatically sus-v tained, and means operable in conjunction with thepiston whereby the original volume of oil is automaticallymaintained bythe replacement of leakage.

11. The combination in a vehicle, of the a body and an axle thereof, anair cylinder-j supported on one of said parts and a piston connected tothe other of said parts and working in the cylinder, an air compressoron the vehicle connected with the cylinder to maintain an air pressuretherein and provide an air cushion for the piston, said cylinder havinga valved fluid connection between opposlte sides of the piston, and saidpiston having a part adapted to compress air 12s The combination inv avehicle, of a body, and an axle thereof, an air cylinder having apiston, a fluid connection between opposite ends of the cylinder,means,for supplying compressed air tothe cylinder be=- neath'thepistonto, provide an air cushion therefor,-and an air compressing device insaid-cylinder and operable by the automatic movement of the piston tomaintain normal pressure in the cylinder.

13. In a pneumatic cushioning device,tl1e' I combination of two parts tobe cushioned and movable toward and from each other a cylinder mountedon one part, apiston-1n the cylinder and connected to and.support-- ing.the other part, an mdepenclentsource of airpressure supplyconnectedwith the cylinder and normal y upholding the piston and load, and an aireompresslng device in said cylinder and operable. by the automaticmovement of the piston tomaintain normal pressure in the cylinder.

14. In a 'pneumatlc cushioning: device, the combination of two parts tobe cushioned and movable toward and from each other, a

cylinder mounted on one -.part, a piston in I the cylinder and having anoffset universal joint connection with the other part, a body -of'liquidmaintained bene th the piston and supporting the iston,,sai cylinderhaving' a yielding head et fween which and said piston said liquid iscontained,i'ani air chamber between said yielding head and said bodyof;- a

liquid, and an aircompressing device in said cylinder and operable bythe automatic movement of the pressure in the cylinderl i Y 15, apneumatic cushioning device, the combination of two parts 'to b ecushioned and movable toward and from each other, a

cylinder mounted on one part, a piston in the cylinder'connected withthe other part,

a body of liquid maintainedbeneath the piston andsupporting the piston,sald cyl nder piston to maintain normal 0 having a yielding head betweenwhich and said piston said liquid is contained, an air chamber betweensaid yielding head and said body of liquid, and an air compressingdevice in said cylinder and operable by the automatic movement ofthepiston to maintain normal pressure in the cylinder.

16. The combination in a vehicle, of a body and an axle therefor, aU-shaped air cylinder supported on one of said parts, a

- plston 1n one leg'of said cylinder connected to the other of saidparts, a body of liquid within the cylinder upon which the piston isefiective, the other leg of thecylinder containing a yieldable head, anair chamber between said head and the body of liquid, and an aircompressing device in said cylmder and operable by the automaticmovement of the plston to maintain normal pressure in the cylinder.

17. The combination a vehicle, of a body and an axle therefor, a Ushapedair cylinder supported on one of said parts, a piston in one leg of saidcylinder connected to the other of said parts, a body of-liquid withinthe cylinder upon which the piston is -etl'ective, the other leg of thecylinder containing a yieldable head, an. air chamber between said headand the body of liquid,

means for delivering air under pressure into wltnesses.

LUCIEN R. GRUSS. Witnesses: t Y

C. J. STILSON, ELEANOR F. STILSON.

